2-hydroxynaphthalene-3-monosulpho-6-carboxylic acid and process of making it



Patented July 10, 1928.

UNITED STATES PATENT" OFFICE.

FRIEDRICH KREOKE, OF OFFENBACH, NEAR FBANKFORT-ON-THE-MAINf GERMANY.

ASSIGNOR TO GRASSELLI DYESTUFF CORPORATION, OF NEW YORK, N. Y., A COR- PORATION OF DELAWARE.

2-HYDROXYNAPHTHALENE-S-MONOSULPHO-G-CARBOXYLIC ACID AND PROCESS OF MAKING IT.

No Drawing. Application and June 2, 1927, Serial No. 196,148, grid in Germany June 2c, 1926.

My invention relates to a new 2-hydroxynaphthalene-6-carboxy-monosulphonic acid having probably the formula:

I on nooo soul which acid is obtained by actingjwith sul- 10 phuric acid of at least 1, 82 specific gravity lene-fi-carboxy-disulphonic acid is formed,

which may be converted into 2-hydroxy ,naphthalene-3-monosulpho-6-carboxylic acid by shortly warming the mass of sulphonation, diluted with water.

boxylic oup from the pro not thus obtained, t e well kn0 Wn,2.3-dih droxynaphthalene is obtained, whereby the aforesaid constitution formula of the new monosulphonic acid seems to be very robable.

. The new monosulphonic aci may be used as intermediate for the production of, dyestufis.

The following examples will further illus- 40 'trate my invention, the parts being by weight and all temperatures in centigrade degrees, but it is understood, that my invention is not limited to the particular proporwhile slowly increasing the temperature to tions, reacting conditions or materials listed therein.

Ezvample I are separated by adding common salt, then the mixture of these salts is converted-into the corresponding neutral salts by treatment with sodium carbonate and the neutral solution therefrom is evaporated'until a crystalline separation begins. After cooling down the neutral disodium salt of Q-hydroxynaphthalene-3-monosulpho-6-carboxylic acid separates almost entirely in compact needles. From the filtrate the 2-hydroxynaphthalene-8-monosulpho-6-carbox lic acid may be obtained by adding hydroc loric acid.

By acidifyin a solution oft-he disodium salt the new 2- ydrox naphthalene-3-monosulpho-(S-earboxylic acid is separated. It is soluble in hot water and is diflicultly soluble in dilute acids. By adding common salt to B subjecting the new monosulphonic acid to t e alkali melt and splittin' off the car-' an aqueous solution the acid is converted into the acidsodium salt. The acid is characterized by a blue fluorescence of its solutions in dilute alkali carbonate solutions and the diflicultly soluble'neutral calcium salt.

Example .11.

400 parts" of 2-hydroxynaphthalene-fi-carboxylic acid are slowly introduced at 20-25 in 1000 arts of sulphuric acid monohydrate. imultaneously 900 parts of oleum containing 60% of anhydride are addedand then the mixture is stirred, for some hours 50. The mass ispoured.- on ice by add- Q common salt the acid salt of with t a 2-hydroxynaphthalene G-carboxy-d is 111 phonic acid is formed, which is probably the 2-hydroxynaphthalene-1.3-disulpho -6 -c a r boxylic acid. By shortly warming the aforesaid sulphuric acid solution of the disulphonic acid one sulphonic group is split ofi and the 2-hydroxynaphthalene-3-sulpho-6- carboxylic acid which is diflicultly soluble in dilute sulphuric acid crystallizes almost entirel after cooling down. It is identical lie acid described in Example I.

I claim:

1. As' a new compound a 2-hydroxynaphthalene-6-carboxy-monosulphon1c acid having probably the formula:

nooo 0a:

which is soluble in hot water, diflicultly. soluble in dilute acids, the disodium salt of which crystallizes in compact needles, which acid is characterized by a blue fluorescence of its solutions in dilute alkali carbonate solutions and its diflicultly soluble neutral calcium salt, which acid is substantially identical with that obtainable by acting with sulphuric acid of at least 1,82 specific gravity on Q-hyrdoxynaphthalene-tlcarboxylic aci a c 2. A process for producing a new 2-hydroxynaphthalene-G-carboxy-monosulphonic acid having probably the formula:

H000 O H which process comprises acting with sulphuric acid of at least 1,82 specific gravit on 2-hydroxynaphthalene-6-carboxylic aci 3.- A process for producing a new 2-hydroxyna hthalene-G-carbox -monosulphonic acid having probably the ormula:

H000 soil 'which process comprises acting at moderately elevated temperatures with sulphuric acidof at' least 1,82 specific gravity on 2- hydroxynaphthalene-fi-carboxylic acid.

4. A process for producing a new 2-hydroxynaphthalene fi-carbox -monosnlphonic acid having probably the ormula:

. A. 0H H000 SOSH which process comprises acting at. tempera-v tur'es from about 20-100 with sulphuric acid;of at least 1,82 specific gravity on 2- :1 hydroxynaphthalene-6 carboxylic acid;

5. A process for producing a new 2-hy-' droxlynaphthalene-6-carboxy-monosulphonic acid aving probably the formula:

which process comprises acting at about 5080 with concentrated sulphuric acid'on 2-hydroxynaphthalene-6-carboxylic acid and separating from the mixture of diflerent monosulphonic acids'thus formed the 2-hydroxyna 'hthalene 3 monosulpho-G-carboxylic aci according to the-less solubility of its neutral alkali metal salts. V p

6. A process for producing a new 2-hydrox 'aphthalene-G-carbox -monosulphonic acid aving probably the ormula:

H000 cm which process comprises acting with sulphuric acid containing free anhydride on Q-hydroxynaphthale'ne-(i-carboxylic acid and warming the mass of sulphonation, diluted with water, whereby a 'sulphonic group is split off from the formed disulphonic-acid.

'8. A process for producing a new Q-hydroxynaphthalene-6-carboxy-monosulphonic acidhaving probably the formula:

OH I H000 om which process comprises acting at about 20-50 with sulphuric acid containing free anhydride on 2-hydroxynaphthalcne-G-carboxylic'acid and warming the mass of sulphonation, diluted with water, whereby a sulphonic group is split 01f from the formed disulphonic acid In testimony whereof, I afiix my signature I FRIEDRICH KnEcKE, 

